In 2025, TSA officers continue to intercept millions of prohibited items each year, with firearms, knives, and large tools consistently ranking at the top of the list. According to TSA data, firearms discovered at checkpoints have increased in recent years, and many of those firearms were loaded. The agency emphasizes that even items allowed in checked baggage may be confiscated if found in carry on luggage. Explosives, flammable materials, and oxidizers are strictly forbidden, including certain aerosols, fuel, and lighter fluid. TSA also prohibits items that could be used as a disabling agent, such as certain chemicals and poisons. The agency updates its rules periodically based on threat assessments and international aviation standards.
Liquids, Electronics, and Battery Restrictions
Liquids restrictions remain one of the most common reasons for bag rejection at the checkpoint. All liquids, including water, beverages, soups, and gels, must be in containers of 3.4 ounces or less, and all containers must fit comfortably in a single quart-sized resealable bag. Medications, baby formula, and breast milk are exempt from the 3-1-1 rule but must be declared at the checkpoint for additional screening. Electronics larger than a smartphone, such as laptops, tablets, and cameras, must be removed from bags and placed in separate bins for X-ray screening. Power banks and portable chargers are allowed only in carry on bags, not in checked luggage, and must be under 100 watt hours per device. For devices between 100 and 160 watt hours, airline approval is required. The Federal Aviation Administration provides detailed guidance on lithium battery rules.
Spare lithium batteries, including those for cameras, drones, and e-bikes, are prohibited in checked luggage and must travel in carry on bags. The FAA and the International Civil Aviation Organization have tightened rules on lithium metal and lithium-ion batteries due to fire risks. Batteries with a watt-hour rating above 160 watt hours are generally not allowed on passenger aircraft without special airline and regulatory approval. E-cigarettes, vaping devices, and heated tobacco products are allowed only in carry on bags, not in checked luggage, and must be protected to prevent accidental activation. Spare batteries for such devices should be protected to prevent short circuits. Airlines such as Delta, United, and American Airlines publish their own battery and electronics policies in line with FAA and IATA standards.
Airline-Specific Carry On Restrictions
While TSA sets the baseline for prohibited items, individual airlines impose additional carry on restrictions on size, weight, and item types. Most major U.S. carriers allow one carry on bag plus one personal item, with maximum dimensions typically around 22 by 14 by 9 inches, including handles and wheels. Budget carriers such as Spirit and Frontier enforce stricter size limits and charge for carry on bags that do not fit under the seat. International carriers, including Emirates, Lufthansa, and Qantas, have their own policies that may differ from U.S. rules, especially